1. The Field of the Invention
The present invention relates to procedures that employ endodontic instruments in preparing a root canal of a tooth for receiving a sealer and/or filler material. More particularly, the invention relates to devices, kits, and methods for removing a portion of an endodontic instrument that has broken off the main shaft and become lodged within the root canal being prepared.
2. The Relevant Technology
When a root canal of a living tooth becomes infected or abscessed, discomfort and, in many cases, severe pain can result. In the early days of dentistry the only solution was to pull the tooth. More recently, however, dental practitioners have learned to successfully remove the pulp material that forms the nerve of the tooth, which has become infected. After careful preparation of the canal that contained the nerve material, the canal is refilled with an inert filling material, such as gutta percha. This process allows the patient to retain the tooth.
To achieve a successful root canal restoration, the dental practitioner must carefully and, as completely as possible, remove the infected pulp material. The removal process typically includes shaping the root canal so that it can be effectively and successfully filled and sealed with an inert material to reduce the possibility of further infection.
Cleaning and shaping the root canal in preparation for receiving a sealing and/or filling material is achieved by the use of metal endodontic instruments that include cutting surfaces for removing tissue in the root canal. Since root canals are seldom straight, often having bends and twists, at least some endodontic instruments are flexible so as to allow the instrument to follow the curvature of the root canal. Currently preferred materials of construction include stainless steel and super-elastic alloys, e.g., some nickel-titanium (Ni-Ti) alloys. Although such instruments generally exhibit good flexibility, resilience, and strength, they can sometimes fail during use within a root canal of a tooth, resulting in a broken instrument fragment becoming tightly lodged within the root canal of a tooth.
The consequences of leaving and/or bypassing broken instrument fragments within the root canal can be serious. In some cases, leaving the broken instrument in the tooth can result in later complications that require extraction of the tooth. Because of this, it is generally preferred that the broken instrument be removed from the root canal, if possible, to prevent additional future problems. Still, it has generally been very difficult to remove broken instrument fragments. In particular, most broken instruments are files, drills, bores, or other cutting instruments that broke after becoming wedged inside the structure of the root. Therefore, the very fact that the instrument was broken generally indicates that the instrument became stuck in the tooth structure and could not be easily pulled free. In addition, the instrument often breaks at a point deep within the canal, not easily visible or accessible to the practitioner.
Until now, there has been a lack of simple, efficient, and effective means for removing the broken instrument fragment in order to complete the endodontic procedure, which would be advantageous as removal and subsequent filling and sealing the root canal would minimize the possibility of later infection and/or loss of the tooth. Therefore, what is needed is an extraction tool, related kit, and method that would facilitate simple, efficient, and effective removal of the broken instrument fragment from the root canal.